1. Field of the Invention
The present invention relates to a thermal treatment process in the manufacturing process of semiconductor devices. In particular, the present invention relates to apparatus and method for manufacturing a semiconductor device, which are applied to a heating process when forming electrodes of FeRAM capacitor devices using metal oxide.
2. Description of the Related Art
For instance, in one kind of semiconductor devices, that is, FeRAM (Ferroelectric Random Access Read Memory), the insulating film of capacitor device is formed using oxide ferroelectric material film in order to achieve the number of 1012 rewritable times or more. For example, PZT (Pb—Zr—Ti—O) is given as the above oxide ferroelectric material film. In addition, in the FeRAM, the electrode of the capacitor device is formed using metal oxide conductor in order to prevent the degradation of electrical characteristics of the oxide ferroelectric material film. For example, SRO (SrRuO3) is given as the above metal oxide conductor. The SRO is crystallized, thereby having conductivity. In order to crystallize the SRO, heat treatment process is required when forming SRO electrode.
However, one component of the SRO, that is, Ru is easy to generate a volatile substance, that is, RuO4 in the heat treatment process of the SRO electrode. The generated RuO4 is decomposed after adhering to the surface of the SRO electrode (SRO film); as a result, RuOX crystal particles (abnormal particles) are generated on the surface of the SRO film, as shown in FIG. 4. The above RuOX crystal particles have a diameter of about 0.5 μm or more. For this reason, it is almost impossible to remove the RuOX crystal particles from the SRO electrode by after-cleaning. As a result, the RuOX crystal particles on the SRO electrode has a possibility of causing the operation failure of the capacitor. In addition, the RuOX crystal particles have a possibility of reducing semiconductor device performance, quality and reliability. Consequently, the RuOX crystal particles are a factor of reducing semiconductor device yield, and thus, increasing the manufacturing cost of semiconductor devices.